Some existing articulating arm and tilter designs use a set screw that is driven directly into a bushing of approximately circular cross-sectional area that is positioned around the rotating cylinder of an arm or tilter joint to supply pressure to the rotating cylinder in order to restrict rotation of the attached arm or user device about the rotating cylinder. In these prior art devices, the bushing includes a gap that permits the size of the outer circumference of the bushing to be adjusted when acted upon by the set screw, thus supplying the desired amount of friction to the rotating cylinder. In these devices, proper placement of the gap in the bushing away from the axis of the shaft of the set screw is necessary to ensure that the bushing properly transfers the force to the rotating cylinder that is being applied by the set screw to the bushing. If the gap in the bushing becomes aligned with—or gets too close to being aligned with—the axis of the shaft of the set screw, the gap in the bushing may not close and open as intended in response to movement of the set screw, thus causing the articulating arm joint or tilter to malfunction.
Further, in some prior art articulating arms and tilters, the bushing clamps around only a small portion of the width of the rotating cylinder, which causes clamping forces to be unevenly applied to the rotating cylinder and the set screws to work themselves loose over time.
Accordingly, there is a need for an articulating support arm with an improved friction joint that addresses these and other drawbacks of the prior art.